Increase the port range net.ipv4.ip_local_port_range

There is a possibility that on a highly loaded server, such as a proxy or router, with a very large number of connections, free ports in the allocated range may run out, so you need to look at the current number used and, if necessary, increase the net.ipv4.ip_local_port_range value.

Continue reading “Increase the port range net.ipv4.ip_local_port_range”

Migrating MySQL Directory

Once I created a raid, mounted it as a disk system partition and transferred the MySQL directory directly to it, but in this case there were drawbacks, the lost+found directory could appear, it could not be used for other data, etc., after that I began to transfer the MySQL directory not directly to the partition, but created a directory on it and transferred it to it.

Continue reading “Migrating MySQL Directory”

How to change innodb_io_capacity in MySQL

innodb_io_capacity – determines the number of write IOPS for background InnoDB tasks, such as flushing pages from a buffer pool, etc. If the cleanup operation is lagging, then InnoDB can perform cleanup more aggressively at a higher IOPS, which is defined in the innodb_io_capacity_max variable.

Continue reading “How to change innodb_io_capacity in MySQL”

Installing and configuring xt_NAT

I will give an example of installing and configuring xt_NAT on Ubuntu Server 14.04 with kernel version 4.4.0-142. xt_NAT may not work on newer kernel versions. According to the developer, it should work on Linux Kernel 3.18 and 4.1. To make it work on newer versions of the kernel, you can find patches.

Continue reading “Installing and configuring xt_NAT”